Questions tagged [skew]

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110 views

Forward Volatility vs Spot Volatility in Option Skew Models

My question is regarding Volatility Skew Models and their inputs. I have noticed that a vast majority of models take as an input the forward of the underlying (even in the case of stocks - where the ...
4
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0answers
49 views

Measuring implied move priced into an event

It's well known that options price in an expected move in the underlying going into events, such as earnings announcements. I currently measure this implied move by computing the forward variance ...
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0answers
65 views

Practical Skew Model For Equity Options?

I'm looking for a simple model I can use to calibrate equity implied volatility surface. There are several models published in the literature, and most of them seem far too sophisticated for my ...
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0answers
27 views

Why Jarque - Bera values are so high? Is this normal? [closed]

Please advise whether the following is a normal occurrence: In the above table I have Autocorrelation at lag1, LB, Skew, Kurt and JB test. I have noticed that whenever the value of Kurt increases, ...
2
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0answers
142 views

Fitting Gatheral's SVI model

I was considering using Gatheral's formula for fitting option skew. In the specific (commodity) market that I am concerned with, the underlying is ca. at 50, and typically 5 integer strikes left and ...
3
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2answers
185 views

Fitting Function for Skew

I am faced with having to fit skew/smile to option quotes with different strike and same maturity. In order to keep things reasonably simple and to avoid potential artifacts from fitting higher order ...
10
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1answer
487 views

Variance swap volatility - ATMF vol, Skew and Curvature

In a pure diffusion setting, it is a well known result that the volatility $\sigma_T$ of a fresh-start variance swap of maturity $T$ as seen of $t=0$ verifies \begin{align} \sigma_T^2 &= \Bbb{E}_0^...
6
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0answers
82 views

Produce volatility smile/skew with G2++ model

Suppose I have a G2++ short rate model: $$r(t)=x(t)+y(t)+\phi(t), \quad r(0)=r_0$$ with $$dx(t)=-ax(t)dt+\sigma dW_1(t), \quad x(0)=0$$ $$dy(t)=-bx(t)dt+\eta dW_2(t), \quad y(0)=0$$ $$d\langle W_1,W_2\...
3
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0answers
110 views

Volatility surface fitting, interpolation and extension from sparse data

There are some nice papers about constrained spline fitting essentially giving you a smoothing and arb free surface. I am focusing on the oil market here: The market is essentially split in a very ...
0
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1answer
42 views

How skew in vertical put spreads change the payoff?

An spx four strikes wide Put Spread from at the money has a payoff ratio of 1 to 2 meaning if the Premium on the spread is \$10 your reward is \$20; yet the corresponding Call Spread with the same ...
1
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2answers
154 views

How do you factor in skew when assessing implied volatility for a non-atm option?

If you think volatility is too cheap, how do you decide if an ATM call or an upside call (which trades at lower vol because of skew) is better? Let's say you have a $100 stock. You think the stock ...
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0answers
40 views

Trying to understand Strike Adjusted Spread, can someone explain using a simple example?

I should start by saying that I am not a quant, I am someone interested in options but I perhaps lack the mathematics background to always follow along. I recently stumbled upon a terrific article ...
0
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1answer
344 views

Forward Skew in the Local Volatility Model

How does the local volatility model cause a forward skew? How is this different to the skew observed for future tenors in the vol surface?# Also how do LV models underestimate vol of vol?
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0answers
614 views

Local Stochastic Volatility - Break even levels

In Chapter 12 of his excellent book Stochastic Volatility Modeling, Lorenzo Bergomi discusses the topic of local-stochastic volatility models (LSV). As most of you are probably aware of, the idea is ...
2
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0answers
279 views

Why is Bachelier implied volatility more skewed than the Black-Scholes implied volatility?

I found the following explanation in a paper by Grunspan (see attached paper page 6) but have trouble understanding it: By differentiating Formula (3) with respect to m, it turns out that the ...
7
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1answer
170 views

How are the BKM risk-neutral moments derived?

I've been doing a lot of research on implied volatility skewness, and one of the most commonly cited papers I've come across is "Stock Return Characteristics, Skew Laws, and the Differential Pricing ...
1
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1answer
2k views

Common Quanto adjustment

In this paper (Quanto Skew, by Jackel), on second page, the author states: a) Determine an effective volatility coeffcient $\hat \sigma$ exactly as in (2) using the forward as if the option was ...
1
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1answer
63 views

Detailing a proposition about option pricing model coherence

On page 4 of this paper, the author states the following: "Looking at the limit case, when the strike tends towards 0, we should have the price of a forward contract and it should not depend on ...
2
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0answers
214 views

When is vol smile skew considered high?

There are a lot of ways one could look at this question. I usually define skew to mean the slope of the vol smile in log moneyness space - ie the skew at strike $k_0=log(K_0/F)$ is: $$\frac{d\sigma}...
3
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0answers
167 views

Relationship between Implied Volatility Curve Derivatives and the Underlying's Moments

Very probably this question has been posed before, so if someone can pose the link to the relevant question, it would be appreciated. What is the relationship between the implied volatility skew and ...
5
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4answers
470 views

Asset-Or-Nothing call option price with skew

I have never seen a formula browsing the web for an asset or nothing option price when skew is accounted for. I am surprised I do not see something for this which should be standard in FX since ...
3
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1answer
884 views

Spot and Vol Correlation in Idealised Regimes of the Volatility Surface

From http://www.globalvolatilitysummit.com/wp-content/uploads/2015/10/Santander-Volatility-Trading-Primer-Part-II.pdf it states that there are the four idealised regimes of volatility surface. 1) ...
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1answer
3k views

Skew and shadow delta

The presence of skew causes a correlation between volatility and spot. This correlation produces a negative shadow delta for all forward starting products (forward starting options have a theoretical ...
2
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1answer
1k views

Vol skew and spot-vol correlation

Why does the market assign a vol skew in the presence of a spot vs vol correlation. Both heuristic/fundamental answers as well as mathematical explanations welcomed
1
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1answer
202 views

Volatility Smile/skew in volatile markets

In a volatile market with uncertainty it's more likely that we see a volatility skew and not so much a smile. Therefore it must hold that, in chaotic markets, out-of-the-money calls and in-the-money ...
2
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1answer
148 views

Evaluating trading strategies by the skewness of returns

How to deal with skewness of returns when evaluating different trading strategies? More specifically, I'm back testing different strategies to be implemented as an automated black box strategy. While ...
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3answers
2k views

Why is a variance swap long skew?

I can appreciate the mathematical derivation, but can anyone explain this in a more intuitive sense? I often come across the mistaken belief that due to the replicating portfolio being long more ...
1
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1answer
131 views

SKEW Index as parameter in lognormal distribution

The CBOE publishes a SKEW index, which is SKEW = 100 - 10*S, so from the index itself we can get S = (SKEW - 100)/10. I just ...
1
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1answer
284 views

volatility skew for lognormal model is flat?

Does anyone know why the volatility skew for lognormal model, such as BK, should be a flat line, meaning that implied black volatility for options will be same for those with different strike prices? ...
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1answer
370 views

Does the fact that volatility is not constant imply existence of skew?

I had a question regarding the existence of the volatility skew. I've tried researching it a fair bit and I come across a few different explanations: 1. Market participants like buying downside puts ...
5
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1answer
422 views

Understanding skew of SPX - Why does IV of OTM puts increase with strike?

I've been trying to understand the skew I see when looking at the skew of SPX. Here is a snapshot today from thinkorswim. I understand why IV increases for ITM puts -- namely because there is a ...
4
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3answers
696 views

Why can't you arb skew by buying options with low implied vol and selling high implied vol in the same month and dynamically hedging?

there's something I've been trying to understand for a while now and I just can't quite understand with regards to skew. In the same month, why can't you buy a option that have low implied vol on the ...
0
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1answer
239 views

How do I track implied volatility of specific delta?

I'm a newbie with respects to volatility trading and options. I recently purchased a book on the topic called "Trading Implied Volatility -An introduction" by Simon Gleadall. It's been one of the most ...
1
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1answer
337 views

Skew in Black Scholes model

We are modeling Foreign exchange rates using Black Scholes model given below: $$F_{t}=F_{t−1} + (r_d−r_f)F_{t−1}dt + \sigma F_{t−1}dW_t$$ Where: $F_t$ and $F_{t−1}$ are FX rates at time $t$ and $t−...
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1answer
106 views

Why vertical skew is same for puts and calls

What is the reason that the vertical volatility skew graph(decreasing IV as the strikes increase) is the same for the puts and calls? The loose explanation is because of put call parity, but I am not ...
2
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1answer
2k views

Black Scholes - how to calculate delta with a vol skew

I am trying to calculate the delta of an option at different strike prices where the underlying has a pronounced implied volatility skew in order to correctly hedge an options strategy. Researching ...
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0answers
641 views

Calibration Problem in the LMM-Skew (Shifted Diffusion) Model

I have implemented the LIBOR market model (LMM) and I am quite satisfied with the results. I have now added a skew to the model as described in 10.1 of Brigo/Mercurio. That is, I have replaced the SDE ...
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1answer
146 views

Why doesn't VG flatten volatility skew for short term options?

The VG process, from my inexpert point-of-view, seems to nearly perfectly model equity distributions. For longer term options, there is little to no volatility, skewness, or kurtosis parameter skew. ...
2
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3answers
412 views

Why are short expiries associated with more pronounced volatility skews?

I've noticed that for a given strike price, the shorter expiration dates of options have more pronounced volatilities why is that?
2
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0answers
1k views

Interpolate option volatility in delta space in R

I have a bunch of deltas and option implied vols at those deltas. I would like to interpolate them in R. Interpolating them in delta space seems difficult, since normally you would like the ATM calls ...
4
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1answer
802 views

Why does Skew measure remain more-or-less constant for Listed Expiries?

I have looked at the Variance Swap Papers published by GS-VarSwap and JPM-VarSWap where they talk about approximation to VarSwap strike using ATMF vol and Skew (slope of the volatility skew for 90-110 ...
17
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1answer
6k views

Skewness and Kurtosis under aggregation

Returns possess non-zero skewness and excess kurtosis. If these assets are temporally aggregated both will disappear due to the law of large numbers. To be exact, if we assume IID returns skewness ...
9
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1answer
740 views

Option Portfolio Risk - Volatility/Skew - practical implementation

I'm trying to improve my methods for calculating real-time US Equity option portfolio risk. My main problem is volatility "stability" across all strikes in an option series. The current ...
13
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1answer
2k views

How should I estimate the implied volatility skew term when calculating the skew-adjusted delta?

I'm trying to come up with the implied volatility skew adjusted delta for SPY options. I'm working with the following formula: Skew Adjusted Delta = Black Scholes Delta + Vega * Vol Skew Slope. I ...
21
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3answers
4k views

Is there a popular curve fitting formula of options skew vs strike price or vs Delta?

I was trying to build a options trading/optimization system. But it often gets more inaccurate as it scans through the far from ATM options because, you know, options skews. That is because I did ...
17
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5answers
20k views

What is the implied volatility skew?

I often hear people talking about the skew of the volatility surface, model, etc... but it appears to me that a clear standard definition is not unanimously in place among practitioners. So here is ...